Patent GB-418410-A (GB)
Title: Improvements in and relating to telegraphic tape printing systems
IPC: H04L13/18
Filed: 1933-11-17
Abstract: 418,410. Changing signs. EITZEN, A. D., Rockville Centre, New York, U.S.A. Nov. 17, 1933, No. 32095. [Class 3 (i).] In a telegraphic system having a tape-printing transmitter and one or more tape-printing receivers an exhibiting area is provided at the transmitting and receiving stations through each of which areas passes the respective tape, the areas being of such size and so arranged that at any instant the matter contained on the portion of tape within the area at the transmitting station is the same as that upon the tape within the corresponding areas of the receiving stations, and is directly visible on the area at the transmitting station, but is projected from the areas at the receiving stations on to a screen or the like. Typewriters 1, 4, Fig. 6, of substantially the same design are connected by wiring 5 so that messages &c. typed on the transmitter 4 are typed by the receiver 1 and exhibited on a screen 70 by a light-projection system, the operator of the transmitter 4 being able to visualize what is projected on the screen by looking at an area of the tape which is within a frame 120 mounted in brackets 123 above the platen of the transmitter. The receiver 1 has supporting walls 7, 8, Figs. 2 and 6, provided with extensions 9 on which is adjustably and pivotally mounted a lamp housing 14 provided with a light aperture 42 in front of which the tape T moves after leaving the platen 40 of the typewriter 1. The tape passes from a supply roll 101 mounted on the rear upper end of the typewriter 1, over an idler roll 102, down and around the platen 40, under a guide 43 and across the light aperture 42, over a rubber-faced feed roller 90, Fig. 3, under a feeler-roller 45, and then to a rewind reel R. The roller 45 is mounted on arms 46 pivoted at 47 and is movable to apply brakes 62 to brake drums 55, 59 on the rewind reel R when the tape T becomes taut due to the stoppage of the feeding means on the typewriter. A shaft 49 connected to the brake drum 55 is driven from a motor 6 by a spring belt 51 and sheaves 50, 52. For pulling the tape T a line space in synchronism with the typewriter 1, the line-feed bell-crank lever 71 of the typewriter, which is depressed when the tape T is advanced, is adapted to engage a lever 76, pivotally mounted on a bracket 73 secured to the platform 2 of the typewriter, this lever 76 being pivotally connected to an adjustable link 78 pivotally connected to a lever 79. The lever 79 is pivotally connected at 80 to a bracket 81 fixed on the extension 36 of the lamp housing 14, and its free end has a ball-andsocket connection 82 with one end of a bracket 83 pivotally connected at 84 to the extension 38 of the housing 14. The upper end of the bracket 83 is pivotally connected to a pawl 85 which engages under spring action a ratchetwheel 86 fixed to the feed-roller 90. A second pawl or latch 88 co-operates with the pawl 85 to form a step-by-step escapement. The tape T is held in engagement with the feedroller 90 by pressure rollers 93, 94, 95 mounted on levers 96 pivotally mounted on a rod 97, the levers being urged towards the roller 90 by springs 98 coiled around the rod 97. For withdrawing the pressure rollers to allow a new tape to be threaded through the machine, an arm 100 which is connected to a U-shaped bracket 99 may be manipulated. The connecting means between the bell-crank lever 71 and the ratchet-wheel 86 are such that the feedroller 90 will pull the tape at a slightly faster rate than it is fed by the platen 40, so that the tape is taut across the light aperture 42. The type-bars are each provided with lower and upper case types. In order to effect printing with an upper-case type the platen 40 is moved upwardly, in which case a loop 104 is formed between the platen and the lower edge of the extension 38 of the lamp housing. A device for holding the tape taut across the light aperture 42 when such a loop is formed comprises two rows of discs 108, 115, formed on shafts 105, 114 respectively, which engage the tape at the entrance and exit of the light aperture, both shafts being held in open-ended bearings by springs 116, 117. The frame 120 of the transmitter 4 is adjustably mounted in the brackets 123, and has U-shaped channels at the sides to guide the tape, and an upper and a lower wall. The frame is anchored by setscrews to the brackets at a distance from the platen corresponding to the position of the light aperture 42 of the receiver 1. The transmitter is preferably provided with feeding, pulling, and guiding mechanism as in the receiver. The lamp housing 14 of the receiver 1 comprises a lamp 26, a reflector 23, and condenser lenses 27, 37, and 39, the lenses 37, 39 being cut away to allow the housing to be lowered as near as possible to the platen 40. The lower wall 19 is perforated to permit air from the outside to enter the housing and the end wall of the cover C is provided with a chimney extension 35, Fig. 6, so that the heated air at the top of the housing can be rapidly withdrawn to prevent the formation of heat waves in the housing, and so prevent flickering on the screen 70. An arm 63 formed on the extension 38 of the lamp housing carries an objective lens through which the light passes from the condenser 39 to a mirror or deflector 65 supported on a bracket 66 pivotally mounted at 67 to the extension 68. From the mirror 65 the light rays are directed upwardly on to a mirror or deflector 69, from which they are projected on the screen 70.